Closure for containers embodying lift tab opening means



p 6 YONEKICHI MORIKAWA E M 3,400,851

CLOSURE FOR CONTAINERS EMBODYING LIFT TAB OPENING MEANS Filed April 12, 1967 Fig. I

United States Patent 3,400,851 CLOSURE FOR CONTAINERS EMBODYING LIFT TAB OPENING MEANS Yonekichi Morikawa, Simizu, and Hisayoshi Hihara, Sagamihara, Japan, assignors to Daiwa Can Co., Ltd., Osaka, Japan Filed Apr. 12, 1967, Ser. No. 630,410 Claims priority, application Japan, Apr. 23, 1966,

6 Claims. (Cl. 220-43) ABSTRACT OF THE DISCLOSURE An easily openable closure for containers in which the closure is a cup-shaped plug received in an opening in the top wall of a container, the closure plug having an enlarged lower body portion which bears against a raised skirt formed in the container top Wall as an inverted trough extending around the opening with a force tending to crimp the skirt and thereby establishing a tight joint between the closure and top wall. The trough provided by the raised skirt is filled with a plastic sealant which also extends onto the surface of the closure adjacent therewith, the sealant completely filling the joint and rendering the closure air tight. A lifting tab with which the container can be opened extends laterally of the plug-like body and over the raised skirt.

Background of the invention The present invention relates to a closure for containers being characterized by the facility with which it can be opened with a lifting tab forming part of its structure as well as the degree of air tight seal provided by the closure due to the employment of a plastic sealant filling the joint between the closure and the container wall in which the dispensing opening is formed.

Easily openable container closures which function without need for special opener tools are known in the art. For example, U.S. Patent 2,849,164 describes a closure of a type wherein the openings in the top of a container through which products is dispensed fromthe container are covered by a thin strip or plate, the plate being held in position on the container by engagement with a lip or chime wall encircling the top of the container. The strip has a small tab positioned adjacent the chime wall with which it can be prised from the container top to uncover the openings. This closure has the drawback that it is possible for it to become detached from the container top with rough handling as might occur during shipment. Also this type of closure is not satisfactory for use with certain types of product packed in the container such as those which can generate a gas within the container. Another form of easily operable closure is described in U.S. Patent 2,784,893, the closure of this patent being a metallic reuseable plug which engages with a snap fit in an opening formed at one side of the top of a laminated fiber container. This closure is not suited for use in containers wherein the product is contained under a pressure or is of an acid character. U.S. Patent 2,723,778 describes still another type of easily openable closure for a sealed container intended for use for holding product under pressure wherein a circular slit is formed in the top of the container defining a severance line therein around a removable section in the container top. A metal tab extends through the slit into the container and is connected with the removable section and the severance line is sealed with a sealing compound. The container is opened by lifting the metal tab and thereafter pulling out the removable section with the tab. The disadvantage of this construction is that it involves the user applying two separate "Ice opening movements with the metal tab and produces a razor edge on the removable section which must be prised up by exerting a fair amount of force with the lifting tab thus increasing the hazard that the user can cut himself.

The present invention on the other hand provides a closure for a container which functions to provide an air tight seal of the container effective to bar leakage of the contents when the latter is contained under pressure. Moreover it easily withstands the effects of shock forces produced during rough handling, is acid resistant and finally it can be opened in a single, simple motion with little effort without requiring the use of a special opener tool.

Summary of the invention The closure of the present invention is intended for use with a container having a generally fiat top wall in which is formed an opening, the latter being encircled by a raised skirt which defines the opening. The raised skirt preferably includes an inner side and an outer side joined by a curved crown segment and thus constituting an inverted trough like structure. The closure is a generally cup-shaped plug conforming in plan section with the shape of the opening and has an enlarged lower body portion which bears against the inner side of the raised skirt tending to crimp the inner side and thus forming a tight closure joint therewith. A plastic sealant fills the'inverted trough and also extends onto the surface of the closure lower body portion adjacent the inner side of the raised skirt. In this manner an air tight closure of the container opening is effected. A tab is formed integrally with the body of the closure and extends laterally therefrom over the raised skirt presenting a levering structure positioned closely adjacent the container top wall with which the closure can be easily prised open for emptying the contents from the container.

According to the invention the sealant is preferably formed from a plastisol and either the closure or the container top wall, or both, are made from tin plate.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the construction hereinafter set forth and the scope of the invention will be indicated in the claims.

Brief description of the drawing A fuller understanding of the nature and objects of the present invention will be had from the following detailed description taken in conjunction with the accompanying drawing in which:

FIGURE 1 is a top plan view of the top wall of a container embodying a closure constructed in accordance with the principles of the present invention.

FIGURE 2 is a sectional view as taken along the line II-II in FIGURE 1.

FIGURE 3 is a fragmentary sectional view on enlarged scale of the structure contained within circle A in FIG- URE 2.

Throughout the description like reference numerals are used to denote like parts in the drawing.

Description of the preferred embodiments The closure of the present invention is intended to be used with containers having an opening in the top or upper wall of the container. The closure is characterized by its providing an air tight fit between it and the wall in which is formed the opening, and in that it is capable of withstanding the pressure exerted by the contents of the container when used in conjunction with products such as carbonated beverages and the like.

Referring now to FIGURES 1 and 2, the container 10 with which the closure of the present invention is used, is

of conventional construction, only fragmentary portions of the main wall 11 thereof being shown in FIGURE 2. The container includes a top wall 1 which is of generally flat construction having a flanged periphery as at 12 which receives the container main wall 11, the joinder of these elements being made air tight in the usual manner. As is customary with these containers, the flat top wall 1 is provided with an opening 30 providing access to remove the contents from the container. The present invention contemplates that the opening 30 be formed in the top wall and be encircled by a raised skirt 3 formed from the top wall structure as shown in FIGURE 2. As will be noted in FIGURE 3, the raised skirt is comprised of an inner side 15 and an outer side 16, the latter being integral with flat top wall 1 and being connected with the inner side by means of a rounded crown segment 13. The raised skirt 3 is of a continuous encircling structure, its inner side 15 defining the opening 30, the skirt arrangenrent being such that it presents an inverted trough directed opening in the direction of the bottom of the container. The inner side 15 of the raised skirt is for a reason as will appear later in the description, of lesser height than the outer side and terminates at a lower edge 20 located a distance above the plane of top wall 1.

The closure generally denoted by numeral 2, is a cupshaped plug which is received in the opening 30 and has an enlarged lower body portion as at 24. It will be understood that the closure plug will correspond in plan section with the shape of the opening in top wall 1, the opening 30 being shown by way of example in the drawing as being circular, the plan section of the closure plug correspondingly being circular, the overall plug structure being frustoconical in shape. However, it is possible within the scope of the invention to use other configurations for these features, as for example ellipses.

The closure plug 2 also is provided with a lifting tab 5 which preferably is made integral with the closure plug and extends laterally therefrom above the crown segment 18 of the raised skirt 3 terminating a substantial distance therefrom. The tab 5 thus provides a prising lever with which the closure can be removed when opening the container and only very little force need be employed by the user for that purpose.

Turning now to FIGURE 3, a brief description of the manner in which the closure plug is fitted to the container top will be described. After the container top has been fabricated and the raised skirt and opening formed therein, a closure plug having a substantially cylindrical body as shown in dashed lines is inserted through the opening,

the bottom 26 thereof extending some distance below the I plane of the top wall 1. With a suitable tool, the closure plug is struck outwardly from the inside so as to enlarge the lower body portion thereof producing the configuration shown in solid lines in FIGURE 3. This operation results in the bottom wall 26 of the closure plug being displaced upwardly to a position wherein it is in substantial planar alignment with top wall 1. The character of the enlargement given the closure plug is such that it enlarges outwardly in the direction of bottom thereof and as a consequence is forced into a tight bearing abutment with the inner side 15 of the raised skirt, the termination of the plug lower body periphery being at a location radially outwardly of opening 30. The bearing engagement is such that the closure plug applies a crimp to the inner side 15 of the raised skirt effecting a relatively tight joint between the plug and the inner side. The joint is shown in FIGURE 3 as being at 28 and is such that the plug cannot be removed from the container top wall except by deliberate opening forces applied thereto with lifting tab 5. In other words, under the shock forces attending packaging and shipment of the container, the plug will remain firmly in place. It will be appreciated that the closure is fitted to the top of the container prior to filling the container and securing the top to the main wall 11 of the container.

In one embodiment, the container was provided with a raised skirt having an overall height F above the top wall of 1.4 mm., while the inner side thereof had a height G of .9 mm. The overall height and depth H of the closure plug before enlarging same was 3 mm. which upon enlargement of same was reduced to 1.7 mm. Thus it will be noted that the closure plug should in all cases have a greater height than the raised skirt.

After the closure plug is firmly fitted in the opening 30 as described, the container closure is finished by filling the inverted trough constituted by the raised skirt with a plastic sealant 4. The trough is completely filled and as will be seen in FIGURE 3, the sealant extends over onto the surface of the plug lower body portion adjacent the skirt inner side 15 and invests the joint 28 completely sealing same and rendering the container air tight and capable of withstanding the internal pressure exerted thereon by the contents. When it is thereafter desired to open the container, the user merely applies a levering force to the plug by means of lifting tab 5 breaking the plastic seal and exposing the opening. The materials which can be employed for the sealant 4 can be of various types. However, in the preferred embodiment shown in FIGURE 3, the sealant 4 is formed from a plastisol.

The container of the present invention is well suited for use with products that are of an acid character in which case either the fiat top Wall 1 or the closure plug 2 or both preferably are made of tin plate.

It is believed from the foregoing that the advantages of the closure of the present invention will be apparent. Most notably it allows the container to be opened without use of an opener tool and in one simple, single operation, i.e., a lifting force applied to tab 5. The closure is corrosion resistant, is able to withstand internal container pressure and lends itself to adaptation to existing container manufacturing procedures.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efiiciently attained and, since certain changes can be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accomp'anying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. The combination with a container having a generally flat top wall including an opening therein which is encircled by a raised skirt formed in said top wall in the shape of an inverted trough having an inner side defining the opening, of

a cup-shaped closure plug received in said opening,

said closure plug having a lower body portion which enlarges outwardly in the direction of the bottom thereof and bears tightly against the inner side of said raised skirt in crimping contact therewith, and

a mass of a plastic sealant filling said inverted trough, and extending therefrom onto the surface of said closure plug adjacent the inner side of said raised skirt.

2. The combination of claim 1 wherein said closure plug has a lifting tab extending laterally therefrom over said raised skirt and a distance therefrom.

3. The combination of claim 1 wherein said raised skirt has an outer side integral with said flat wall and is joined with said inner side by a curved crown segment,

the inner side of said raised skirt having a lower edge spaced a distance above the plane of said flat wall,

the lower body portion of said closure cap extending below said lower edge and enlarging outwardly in the direction of the bottom thereof and radially of said lower edge whereby said lower body portion engages said inner side with a bearing contact tend- 5 6 ing to crimp said inner side In the direction of said References Cited Outer side- UNIT D STATE PATENTS 4. The combination of claim 3 wherein the lower body a E S portion of said closure plug has a relatively flat bottom 3,215,306 11/1965 Simpson et a1 220-54 wall extending in substantially planar alignment with the 5 3308986 3/1967 Balocca at 220 53 flat top wall of said container. FOREIGN PATENTS 5. The combination of claim 3 wherein the opening in said top wall is substantially circular, said closure plug being substantially frusto-conical in shape.

6. The combination of claim 1 wherein said plastic 10 sealant is from a plastisol.

1,129,225 9/1956 France.

THERON E. CONDON, Primary Examiner. GEORGE T. HALL, Assistant Examiner. 

